[oslc-core] Addition to Link Guidance: don't make assumptions about links

[Dave]

Jim Conallen and Ian Green wrote the guidance below on links and I've
added it to the Link Guidance document for your review. I think it
offers good advice and stops short of making mandates, which is also
good. Thoughts?

Thanks,
Dave


The new guidance:

Don't make assumptions about the target of links

Relationships in OSLC resources are at their simplest an RDF property
whose object is a URI. Some properties require and assume a resource
of a particular type as the target for a given link type. In general
however, it is considered a good design not to make type assumptions
on the target of links. It is also considered a bad practice to embed
in the predicate name assumptions of the resource type of the object.
For example the link type oslc:implementedByChangeRequest implies the
target resource is a Change Request. Instead the preferred type would
be oslc:implementedBy.

As resources evolve over time, and they adapt to different situations,
different types will be exposed as targets to existing link types.
Well behaved clients should gracefully handle resource types it
doesn't expect when exercising links in resources.

Link:
http://open-services.net/bin/view/Main/OSLCCoreLinksDRAFT#Don_t_make_assumptions_about_the